[Update] Commonize more RTL across the N6001 variants

[DouglasGroen]

Description

Updating the ofs_plat_afu and afu files across the 4 N6001 variants. Also the package and header files. Duplicated some files into variants that don't require them with the idea that they'll exist like that once we've merged all code into a single set of files.

Collateral (docs, reports, design examples, case IDs):

• [ ] Document Update Required? (Specify FIM/AFU/Scripts)

Tests added:

Tests run:

Successful compilations of boardtest, simple-host-streaming, and io-streaming-multi. Further testing is still required (build more designs and validate in-system).

[DouglasGroen]

Moved to a new branch. Closing this for now.